To: Kevin Trenberth
Subject: Re: ppt for LA2
Date: Thu May 5 08:08:55 2005
Apologies
Phil
Kevin,
Finally gotten around to putting thoughts down. Mostly on the challenges slides
at the start. Maybe you would have said these things.
1. As well as suggesting the model chapters rank models (I don't think they will
go with this - even though it is what we should be doing, and there are a whole raft
of issues as to how to do it) should we also be dismissing observational papers
that are clearly wrong (or a distortion of the facts and emphasizing the wrong issues).
In some parts of our chapter, we omit the poor papers. Just stressing that we are
doing an assessment and not a review. An assessment is our expert view of the science
at the present.
For space limitations we must omit many papers, but we must do this objectively. In the
NRC review I made the point that most of the papers reviewed were the author's own. It is
difficult and we must not fall into that trap. All this again comes back to
assessment/review.
With 3.4.1 we mustn't get caught up in having to agree with the CCSP VTT report. We're
either doing OUR assessment or we might as well give up.
Gone on for long enough on that one.
2. I think we both believe we should be saying somewhere what we should be measuring
(how accurately, where and with what). If we don't say this somewhere, AR5 will be in a
worse state. Susan is against this, but I think on this point she's wrong. IPCC has a lot
of clout - much more than GCOS and/or WMO. It should be saying something about what
we should be doing.
3. Minor point, just land warming more than ocean, not much more.
4. I guess you've expanded on linear trends enough
5. The CCSP diagrams are good, but I'm not keen on running means. I guess though they
wouldn't be too different with a better smoother.
6. I guess you'll raise map projections. Could add in the new one Dave has done for precip
to show the 30E edge.
The additional slides. Most of these are from a talk I have to give in Bern next month.
They relate
mostly to issues with Ch 6. Maybe you can add a couple of them.They relate to the issues
of:
- making full use of the instrumental records to compare with proxy records
- changes in seasonality
- was the few hundred years before 1850 always colder than the post 1920 period.
The first 2 are the longest European records. The period I'm interested in is the rise
up
from the late 17th century to the 1730s and then the year 1740. No volcanoes for 20-30
year period may be a factor, solar also, but nothing explains 1740. It is not just in CET.
1730s at CET and De Bilt is the warmest decade until the 1990s. Producing these sorts
of things in proxy data is a key.
3rd slide is just some of these longer records filtered. They don't agree that well, so
why should proxy series agree. We have more to learn from the early instrumental period.
4th is just a simple example of instrumental/proxy overlap. Highlights seasonality
differences.
and 5th just shows how unusual the central European summer was in 2003 - if we
wanted a figure for the box.
The interface with Ch 6 and the early instrumental period is crucial. 60% of the
comments
on Ch 6 were on the 3-4 pages on the last millennium ! Ours weren't that distorted to
one
of our sections.
Issues at UEA and CRU haven't helped me get to 3.2 yet. I hope to by the end of the
day.
Cheers
Phil
At 15:26 03/05/2005, you wrote:
Phil
Did you look at and have comments/suggestion on the ppt for the last day in Beijing?
Kevin
--
****************
Kevin E. Trenberth e-mail: trenbert@ucar.edu
Climate Analysis Section, NCAR [1]www.cgd.ucar.edu/cas/
P. O. Box 3000, (303) 497 1318
Boulder, CO 80307 (303) 497 1333 (fax)
Street address: 1850 Table Mesa Drive, Boulder, CO 80303
Prof. Phil Jones
Climatic Research Unit Telephone +44 (0) 1603 592090
School of Environmental Sciences Fax +44 (0) 1603 507784
University of East Anglia
Norwich Email p.jones@uea.ac.uk
NR4 7TJ
UK
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References
1. http://www.cgd.ucar.edu/cas/